Modifying the Database
We have 3 kinds of modifications: insertion, deletion, update.
Insertion: general form --
INSERT INTO R(A1,…., An) VALUES (v1,…., vn)
Insert a new purchase to the database:
INSERT INTO Purchase(buyer, seller, product, store)
VALUES (‘Joe’, ‘Fred’, ‘wakeup-clock-espresso-machine’
If we don’t provide all the attributes of R, they will be filled with NULL.
We can drop the attribute names if we’re providing all of them in order.